Exploring the Dual Inhibitory Activity of Novel Anthranilic Acid Derivatives towards α-Glucosidase and Glycogen Phosphorylase Antidiabetic Targets: Design, In Vitro Enzyme Assay, and Docking Studies

A few new anthranilate diamide derivatives, 3a–e, 5a–c and 7a–d, were designed, synthesized, and evaluated for their inhibitory activity against two interesting antidiabetic targets, α-glucosidase and glycogen phosphorylase enzymes. Different instrumental analytical tools were applied in identification and conformation of their structures like; (13)C NMR, (1)H NMR and elemental analysis. The screening of the novel compounds showed potent inhibitory activity with nanomolar concentration values. The most active compounds (5c) and (7b) showed the highest inhibitory activity against α-glucosidase and glycogen phosphorylase enzymes IC(50) = 0.01247 ± 0.01 µM and IC(50) = 0.01372 ± 0.03 µM, respectively. In addition, in vivo testing of the highly potent α-glucosidase inhibitor (7b) on rats with DTZ-induced diabetes was done and showed significant reduction of blood glucose levels compared to the reference drug. Furthermore, a molecular docking study was performed to help understand the binding interactions of the most active analogs with these two enzymes. The data obtained from the molecular modeling were correlated with those obtained from the biological screening. These data showed considerable antidiabetic activity for these newly synthesized compounds.